The present invention is directed to an anchor lock fastening assembly (ALFA) which provides the function of holding the rail to the railroad tie while at the same time preventing longitudinal displacement of the rail. More particularly, the present invention is directed in one embodiment to an anchor lock hook plate which readily adapts to an existing tie plate and which controls rail rotation and rail uplift without adding strain to that portion of the anchor which is in contact with the tie and also provides longitudinal restraint to the rail.
In prior art anchor locking devices, the anchor lock is welded to the existing tie plate which introduces an element of work with stringent quality control requirements. Based on the fact that the carbon content can vary greatly from one steel plate to the next, the field experience with welded rail fastening components has not been entirely satisfactory. Since fastenings are subjected to pulsating loads and vibrations in a wide range of frequencies, the fatigue strength of a weldment would be tested to the extreme. A riveted connection is feasible but is considered to expensive.
Accordingly, an object of the present invention is to provide an anchor lock that functions to restrain both righthand and lefthand rotation of the rail.
A further object of the present invention is to provide anchor locks which permit the utilization of existing tie plates to form an anchor lock assembly without modifying or welding the plate.
Still another object of the present invention is to provide a load free anchor lock assembly wherein the anchor lock hook plate is positioned by the existing plate holding spikes in cooperation with down holding hooks which are part of the anchor lock hook plate.
Still another object of the present invention is to provide an insulating member which is effective in providing electrical insulation between the railroad tie and the anchor and which also functions to occupy the space between the anchor and the base of the rail thereby preventing the accumulation of ice between the anchor and the base of the rail.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. to the present invention, a positive lock for a floating rail has been developed as an attachment to an existing tie plate wherein the rail hold down forces are transmitted to the bottom surface of the tie plate by means of downholding hooks which are part of the anchor lock.